CVE-2024-40640 json
Usage of non-constant time base64 decoder could lead to leakage of secret key material in vodozemac
published 2024-07-17 2 y ago modified 2026-10-12 27 d ago also GHSA-j8cm-g7r6-hfpq , RUSTSEC-2024-0354 , EUVD-2024-2372
- cvss
- 2.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 9%
- public exploits
- 0
- none known
Summary
vodozemac is an open source implementation of Olm and Megolm in pure Rust. Versions before 0.7.0 of vodozemac use a non-constant time base64 implementation for importing key material for Megolm group sessions and `PkDecryption` Ed25519 secret keys. This flaw might allow an attacker to infer some information about the secret key material through a side-channel attack. The use of a non-constant time base64 implementation might allow an attacker to observe timing variations in the encoding and decoding operations of the secret key material. This could potentially provide insights into the underlying secret key material. The impact of this vulnerability is considered low because exploiting the attacker is required to have access to high precision timing measurements, as well as repeated access to the base64 encoding or decoding processes. Additionally, the estimated leakage amount is bounded and low according to the referenced paper. This has been patched in commit 734b6c6948d4b2bdee3dd8b4efa591d93a61d272 which has been included in release version 0.7.0. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Patch / fix
- crates.io vodozemac 0.7.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 y ago
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 2.9 | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | vodozemac | <0.7.0 >=0.0.0-0, <0.7.0 |
0.7.0 |
Affected products
- matrix-org vodozemac
Classification
- Weakness
-
- CWE-208 Observable Timing Discrepancy
References
-
github.com
/matrix-org/vodozemac/commit/734b6c6948d4b2bdee3dd8b4efa591d93a61d272
web
-
github.com
/matrix-org/vodozemac/commit/77765dace11266ef9523301624a01265c6e0f790
web
-
github.com
/matrix-org/vodozemac/security/advisories/GHSA-j8cm-g7r6-hfpq
web
-
arxiv.org
/abs/2108.04600
web
-
nvd.nist.gov
/vuln/detail/CVE-2024-40640
advisory
-
github.com
/matrix-org/vodozemac
package
-
rustsec.org
/advisories/RUSTSEC-2024-0354.html
web, advisory
-
crates.io
/crates/vodozemac
package
Sources
- CVE List CVE-2024-40640
- GitHub Advisory GHSA-j8cm-g7r6-hfpq
- NVD CVE-2024-40640
- OSV RUSTSEC-2024-0354
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